Aerosol-generating system with liquid aerosol-forming substrate identification

ABSTRACT

An aerosol-generating system includes a storage portion configured to hold an aerosol-forming substrate, a first electrode, a second electrode spaced from the first electrode, and a control system. At least a portion of the storage portion is between the first electrode and the second electrode. The portion of the storage portion between the first electrode and the second electrode holds the aerosol-forming substrate when the aerosol-forming substrate is held in the storage portion. The control system is configured to measure an electrical quantity between the first electrode and the second electrode, and identify the liquid aerosol-forming substrate held in the storage portion based on the measured electrical quantity information.

This is a continuation of and claims priority to PCT/EP2017/052916 filedon Feb. 9, 2017, and further claims priority to EP 16155571.9 filed onFeb. 12, 2016; both of which are hereby incorporated by reference intheir entirety.

BACKGROUND

At least one example embodiment relates to aerosol-generating systemsand cartridges for aerosol-generating systems. The aerosol-generatingsystems may be electrically operated vaping systems.

One type of aerosol-generating system is an electrically operated vapingsystem. Electrically operated vaping systems typically comprise a liquidaerosol-forming substrate, which is atomized to form an aerosol.Electrically operated vaping systems often comprise a power supply, aliquid-storage portion for holding a supply of liquid aerosol-formingsubstrate and an atomizer or heater. A heater used in electronicallyoperated vaping systems may comprise a coil of heater wire wound aroundan elongate wick soaked in liquid aerosol-forming substrate.

Liquid aerosol-forming substrates may have different compositions.Different compositions of liquid aerosol-forming substrates may havedifferent properties. Some liquid aerosol-forming substrates may not besuitable for use with some aerosol-generating systems. Some liquidaerosol-forming substrates may be damaged or spoiled by hightemperatures. Some liquid aerosol-forming substrates have relativelyhigh viscosities and may not be effectively atomized by certainaerosol-generators.

A manufacturer of an aerosol-generating system may authorize certainliquid aerosol-forming substrates for use in their aerosol-generatingsystems. Authorized liquid aerosol-forming substrates may have suitableproperties for use in the aerosol-generating system. However, an adultvaper may refill the liquid storage portion with an unauthorized andunsuitable liquid aerosol-forming substrate or may use an unauthorizedcartridge holding an unauthorized and unsuitable liquid aerosol-formingsubstrate. Some unauthorized liquid aerosol-forming substrates maydamage the aerosol-generating system. Some unauthorized liquidaerosol-forming substrates may be harmful to an adult vaper.

It would be desirable for an aerosol-generating system to be able todistinguish between liquid aerosol-forming substrates having differentcompositions. It would be desirable for an aerosol-generating system tobe adjustable for use with different liquid aerosol-forming substratecompositions. It would be desirable for an aerosol-generating system toinform an adult vaper of authorized or unauthorized liquidaerosol-forming substrates held in the liquid storage portion.

SUMMARY

In at least one example embodiment, an aerosol-generating systemcomprises: a storage portion configured to hold an aerosol-formingsubstrate; a first electrode; a second electrode spaced from the firstelectrode; and a control system. The first electrode and the secondelectrode are arranged such that at least a portion of the storageportion is between the first electrode and the second electrode. Theportion of the liquid storage portion between the first electrode andthe second electrode stores the aerosol-forming substrate whenaerosol-forming substrate is held in the storage portion. The controlsystem is configured to: measure an electrical quantity between thefirst electrode and the second electrode, and identify theaerosol-forming substrate held in the storage portion based on themeasured electrical quantity information.

Identifying the aerosol-forming substrate held in the storage portionmay enable the aerosol-generating system or an adult vaper to identifyan unsuitable, unauthorized, or unknown aerosol-forming substrate heldin the storage portion. This may substantially prevent and/or reduce useof aerosol-forming substrates that may cause damage to theaerosol-generating system. This may substantially prevent and/or reduceuse of liquid aerosol-forming substrates that are potentially harmful tothe adult vaper. Identification of the liquid aerosol-forming substrateheld in the liquid storage portion may also enable theaerosol-generating system to distinguish between suitable or authenticliquid aerosol-forming substrates. This may enable theaerosol-generating system to be operated in different modes depending onthe identity of the liquid aerosol-forming substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

Example embodiments will be further described, by way of example only,with reference to the accompanying drawings.

FIG. 1 is a schematic illustration of an aerosol-generating systemaccording to at least one example embodiment.

FIG. 2 is an illustration of a liquid storage portion for anaerosol-generating system according to at least one example embodiment.

FIG. 3 is an illustration of a liquid storage portion for anaerosol-generating system according to at least one example embodiment.

FIG. 4 is an illustration of a liquid storage portion for anaerosol-generating system according to at least one example embodiment.

FIG. 5 is an illustration of a liquid storage portion for anaerosol-generating system according to at least one example embodiment.

FIG. 6 is an illustration of a liquid storage portion for anaerosol-generating system according to at least one example embodiment.

FIG. 7 is an illustration of a sensor comprising interdigitatedelectrodes according to at least one example embodiment.

FIG. 8 is an illustration of a sensor comprising interdigitatedelectrodes according to at least one example embodiment.

FIG. 9 is an illustration of a liquid storage portion for anaerosol-generating system according to at least one example embodiment.

FIG. 10 is an illustration of a liquid storage portion for anaerosol-generating system according to at least one example embodiment.

FIG. 11 is an illustration of a liquid storage portion for anaerosol-generating system according to at least one example embodiment.

FIG. 12 is a schematic circuit diagram for a sensor according to atleast one example embodiment.

DETAILED DESCRIPTION

Various example embodiments will now be described more fully withreference to the accompanying drawings in which some example embodimentsare shown. However, specific structural and functional details disclosedherein are merely representative for purposes of describing exampleembodiments. Thus, the embodiments may be embodied in many alternateforms and should not be construed as limited to only example embodimentsset forth herein. Therefore, it should be understood that there is nointent to limit example embodiments to the particular forms disclosed,but on the contrary, example embodiments are to cover all modifications,equivalents, and alternatives falling within the scope.

In the drawings, the thicknesses of layers and regions may beexaggerated for clarity, and like numbers refer to like elementsthroughout the description of the figures.

Although the terms first, second, etc. may be used herein to describevarious elements, these elements should not be limited by these terms.These terms are only used to distinguish one element from another. Forexample, a first element could be termed a second element, and,similarly, a second element could be termed a first element, withoutdeparting from the scope of example embodiments. As used herein, theterm “and/or” includes any and all combinations of one or more of theassociated listed items.

It will be understood that, if an element is referred to as being“connected” or “coupled” to another element, it can be directlyconnected, or coupled, to the other element or intervening elements maybe present. In contrast, if an element is referred to as being “directlyconnected” or “directly coupled” to another element, there are nointervening elements present. Other words used to describe therelationship between elements should be interpreted in a like fashion(e.g., “between” versus “directly between,” “adjacent” versus “directlyadjacent,” etc.).

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of exampleembodiments. As used herein, the singular forms “a,” “an” and “the” areintended to include the plural forms as well, unless the context clearlyindicates otherwise. It will be further understood that the terms“comprises,” “comprising,” “includes” and/or “including,” if usedherein, specify the presence of stated features, integers, steps,operations, elements and/or components, but do not preclude the presenceor addition of one or more other features, integers, steps, operations,elements, components and/or groups thereof.

Spatially relative terms (e.g., “beneath,” “below,” “lower,” “above,”“upper” and the like) may be used herein for ease of description todescribe one element or a relationship between a feature and anotherelement or feature as illustrated in the figures. It will be understoodthat the spatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. For example, if the device in thefigures is turned over, elements described as “below” or “beneath” otherelements or features would then be oriented “above” the other elementsor features. Thus, for example, the term “below” can encompass both anorientation that is above, as well as, below. The device may beotherwise oriented (rotated 90 degrees or viewed or referenced at otherorientations) and the spatially relative descriptors used herein shouldbe interpreted accordingly.

Example embodiments are described herein with reference tocross-sectional illustrations that are schematic illustrations ofidealized embodiments (and intermediate structures). As such, variationsfrom the shapes of the illustrations as a result, for example, ofmanufacturing techniques and/or tolerances, may be expected. Thus,example embodiments should not be construed as limited to the particularshapes of regions illustrated herein but may include deviations inshapes that result, for example, from manufacturing. For example, animplanted region illustrated as a rectangle may have rounded or curvedfeatures and/or a gradient (e.g., of implant concentration) at its edgesrather than an abrupt change from an implanted region to a non-implantedregion. Likewise, a buried region formed by implantation may result insome implantation in the region between the buried region and thesurface through which the implantation may take place. Thus, the regionsillustrated in the figures are schematic in nature and their shapes donot necessarily illustrate the actual shape of a region of a device anddo not limit the scope.

It should also be noted that in some alternative implementations, thefunctions/acts noted may occur out of the order noted in the figures.For example, two figures shown in succession may in fact be executedsubstantially concurrently or may sometimes be executed in the reverseorder, depending upon the functionality/acts involved.

Although corresponding plan views and/or perspective views of somecross-sectional view(s) may not be shown, the cross-sectional view(s) ofdevice structures illustrated herein provide support for a plurality ofdevice structures that extend along two different directions as would beillustrated in a plan view, and/or in three different directions aswould be illustrated in a perspective view. The two different directionsmay or may not be orthogonal to each other. The three differentdirections may include a third direction that may be orthogonal to thetwo different directions. The plurality of device structures may beintegrated in a same electronic device. For example, when a devicestructure (e.g., a memory cell structure or a transistor structure) isillustrated in a cross-sectional view, an electronic device may includea plurality of the device structures (e.g., memory cell structures ortransistor structures), as would be illustrated by a plan view of theelectronic device. The plurality of device structures may be arranged inan array and/or in a two-dimensional pattern.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which example embodiments belong. Itwill be further understood that terms, such as those defined in commonlyused dictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art andwill not be interpreted in an idealized or overly formal sense unlessexpressly so defined herein.

Unless specifically stated otherwise, or as is apparent from thediscussion, terms such as “processing” or “computing” or “calculating”or “determining” or “displaying” or the like, refer to the action andprocesses of a computer system, or similar electronic computing device,that manipulates and transforms data represented as physical, electronicquantities within the computer system's registers and memories intoother data similarly represented as physical quantities within thecomputer system memories or registers or other such information storage,transmission or display devices.

As disclosed herein, the term “storage medium”, “computer readablestorage medium” or “non-transitory computer readable storage medium,”may represent one or more devices for storing data, including read onlymemory (ROM), random access memory (RAM), magnetic RAM, core memory,magnetic disk storage mediums, optical storage mediums, flash memorydevices and/or other tangible machine readable mediums for storinginformation. The term “computer-readable medium” may include, but is notlimited to, portable or fixed storage devices, optical storage devices,and various other mediums capable of storing, containing or carryinginstruction(s) and/or data.

Furthermore, at least some portions of example embodiments may beimplemented by hardware, software, firmware, middleware, microcode,hardware description languages, or any combination thereof. Whenimplemented in software, firmware, middleware or microcode, the programcode or code segments to perform the necessary tasks may be stored in amachine or computer readable medium such as a computer readable storagemedium. When implemented in software, processor(s), processingcircuit(s), or processing unit(s) may be programmed to perform thenecessary tasks, thereby being transformed into special purposeprocessor(s) or computer(s).

A code segment may represent a procedure, function, subprogram, program,routine, subroutine, module, software package, class, or any combinationof instructions, data structures or program statements. A code segmentmay be coupled to another code segment or a hardware circuit by passingand/or receiving information, data, arguments, parameters or memorycontents. Information, arguments, parameters, data, etc. may be passed,forwarded, or transmitted via any suitable means including memorysharing, message passing, token passing, network transmission, etc.

In order to more specifically describe example embodiments, variousfeatures will be described in detail with reference to the attacheddrawings. However, example embodiments described are not limitedthereto.

As used herein with reference to example embodiments, the term‘electrical quantity’ is used to describe any electrical property,parameter or attribute of a system that can be quantified bymeasurement. For example, suitable ‘electrical quantities’ includeimpedance, capacitance and resistance. The control system may beconfigured to measure at least one of impedance, capacitance andresistance.

As used herein with reference to the example embodiments, the term“identify” is used to describe verification, authentication orrecognition of a liquid aerosol-forming substrate. For example,identifying a liquid aerosol-forming substrate may include determiningat least one of the composition of the liquid aerosol-forming substrate,the suitability of the liquid aerosol-forming substrate for use in theaerosol-generating system and the origin or authenticity of the liquidaerosol-forming substrate. Similarly, as used herein, the term‘identity’ is used to describe at least one of the composition, thesuitability and the authenticity of the liquid aerosol-formingsubstrate.

Liquid aerosol-forming substrates may comprise one or more constituents.Liquid aerosol-forming substrates may comprise one or more mainconstituents, such as glycerine and propylene. Liquid aerosol-formingsubstrates may comprise substantially different proportions of the mainconstituents. Variations in the compositions and the proportions of themain constituents may substantially vary the electrical properties ofliquid aerosol-forming substrates. The variation in the electricalproperties of liquid aerosol-forming substrates may be such that aliquid aerosol-forming substrate may be identified by its electricalproperties.

In at least one example embodiment, the aerosol-generating systemcomprises a liquid storage portion for holding a liquid aerosol-formingsubstrate. The electrical properties of the liquid storage portion maydepend on the electrical properties of the liquid aerosol-formingsubstrate held in the liquid storage portion. The aerosol-generatingsystem is configured to monitor an electrical property of the liquidstorage portion. This is achieved by arranging at least a portion of theliquid storage portion holding liquid aerosol-forming substrate betweena first electrode and a second electrode and configuring the controlsystem to measure an electrical quantity between the first electrode andthe second electrode. As such, the control system is configured tomeasure an electrical quantity across at least a portion of the liquidstorage portion holding liquid aerosol-forming substrate (unless theliquid aerosol-forming substrate has been exhausted or depleted from theliquid storage portion). The control system is further configured to usethe measurements of the electrical quantity to identify the liquidaerosol-forming substrate held in the liquid storage portion.

The liquid storage portion may hold liquid aerosol-forming substrate.The liquid storage portion may also comprise one or more of air held inthe liquid storage portion, a carrier material for holding the liquidaerosol-forming substrate, and a housing for holding the liquidaerosol-forming substrate. The liquid aerosol-forming substrate, air,carrier material and housing may have different electrical properties.

The liquid storage portion may comprise an electrical load. The liquidstorage portion may comprise at least one of a resistive load and acapacitive load. Electrical quantities of resistive and capacitive loadsmay be measured without requiring complex electronics.

The first and second electrodes may be arranged such that liquidaerosol-forming substrate held in the liquid storage portion is betweenthe first and second electrodes. The first and second electrodes mayalso be arranged such that one or more of the air held in the liquidstorage portion, the carrier material, and the housing are arrangedbetween the second electrodes. The first and second electrodes may bearranged in contact with liquid aerosol-forming substrate held in theliquid storage portion. The first and second electrodes may be arrangedin contact with the carrier material. The first and second electrodesmay be arranged in contact with the housing.

Liquid aerosol-forming substrates produced or approved by a manufacturerof an aerosol-generating system may comprise constituents that producespecific, recognizable electrical quantity information when measured bythe control system. The control system may be configured to identifywhether the liquid aerosol-forming substrate held in the liquid storageportion is a liquid aerosol-forming substrate produced or approved bythe manufacturer. In other words, the control system may be configuredto determine whether the liquid aerosol-forming substrate is authentic.

More than one liquid aerosol-forming substrate may be suitable for usein the aerosol-generating system. Liquid aerosol-forming substrateshaving compositions that are suitable for use in an aerosol-generatingsystem may produce one or more ranges of specific, recognizableelectrical quantity information when measured by the control system. Thecontrol system may be configured to differentiate between liquidaerosol-forming substrates that are suitable for use in theaerosol-generating system and liquid aerosol-forming substrates that areunsuitable for use in the aerosol-generating system based on themeasured electrical quantity information. In other words, the controlsystem may be configured to identify whether the measured electricalquantity information matches an expected value or range of values for aliquid aerosol-forming substrate that is suitable for use in theaerosol-generating system.

The control system may be configured to determine the composition of theliquid aerosol-forming substrate based on the measured electricalquantity information. Certain constituents of a liquid aerosol-formingsubstrate may substantially affect the electrical properties of a liquidaerosol-forming substrate. A manufacturer may produce two or more liquidaerosol-forming substrates comprising different proportions of aconstituent that substantially affects the electrical properties of aliquid aerosol-forming substrate. The control system may be configuredto distinguish between the two or more liquid aerosol-forming substratesproduced or authorized by the manufacturer based on the measuredelectrical quantity information.

The control system may be configured to identify the liquidaerosol-forming substrate held in the liquid storage portion bycomparison. The control system may be configured to compare the measuredelectrical quantity information to reference electrical quantityinformation stored in the control system.

Reference electrical quantity information may be stored in a memory ofthe control system. The reference electrical quantity information may beelectrical quantity information measured by the control system andstored in a memory of the control system. The reference electricalquantity information may be associated with liquid aerosol-formingsubstrate identity information. This may enable the identification ofthe liquid aerosol-forming substrate held in the liquid storage portionto be reliable.

The reference electrical quantity information may comprise a pluralityof ranges of reference electrical quantity information. Each range ofthe reference electrical quantity information may be associated with aliquid aerosol-forming substrate. The control system may be configuredto compare and match measured electrical quantity information to astored range of reference electrical quantity information.

The reference electrical quantity information may comprise one or moredesired (or, alternatively a predetermined) thresholds. The controlsystem may be configured to compare the measured electrical quantityinformation to the one or more desired (or, alternatively apredetermined) thresholds. The control system may be configured toidentify the liquid aerosol-forming substrate if the measured electricalquantity information does not exceed the one or more thresholds. Thecontrol system may be configured to identify the liquid aerosol-formingsubstrate held in the liquid storage portion as a suitable, authorizedor authentic liquid aerosol-forming substrate when the measuredelectrical quantity information does not exceed a desired (or,alternatively a predetermined) threshold. The control system may beconfigured to identify the liquid aerosol-forming substrate held in theliquid storage portion as an unsuitable, unauthorized or an unknownliquid aerosol-forming substrate when the measured electrical quantityinformation exceeds a desired (or, alternatively a predetermined)threshold.

As used herein, a measurement that exceeds a desired (or, alternativelya predetermined) threshold may be one of a value that is above thedesired (or, alternatively a predetermined) threshold or a value that isbelow the desired (or, alternatively a predetermined) threshold. Inother words, a value that does not exceed the desired (or, alternativelya predetermined) threshold is a value that is within a desired (or,alternatively a predetermined) range.

The reference electrical quantity information may be stored in a lookuptable. The lookup table may comprise stored reference electricalquantity information and stored liquid aerosol-forming substrateidentity information. The stored reference electrical quantityinformation may be associated with the stored liquid aerosol-formingsubstrate identity information. The stored liquid aerosol-formingsubstrate identity information may comprise one or more of compositioninformation, authenticity information and suitability information.

The control system may be configured to indicate to an adult vaper thedetermined identity of liquid aerosol-forming substrate held in theliquid storage portion.

The aerosol-generating system may further comprise an aerosol-generatorconfigured to receive liquid aerosol-forming substrate from the liquidstorage portion. The control system may be further configured to controloperation of the aerosol-generator based on the determined identity ofthe liquid aerosol-forming substrate held in the liquid storage portion.This may enable the aerosol-generating system to operate theaerosol-generator in different modes, such as at different temperaturesthat are most appropriate for different compositions of liquidaerosol-forming substrates. This may enable the aerosol-generatingsystem to disable and/or substantially prevent operation of theaerosol-generator if an unsuitable, unauthorized or unknown liquidaerosol-generating substrate is identified.

As used herein with reference to the example embodiments, controllingoperation of the aerosol-generator includes, amongst other things:controlling the power supplied to the aerosol-generator, controlling thetemperature of the aerosol-generator, controlling the duration ofoperation of the aerosol-generator, and disabling and/or substantiallypreventing operation of the aerosol-generator.

The control system may be configured to measure the electrical quantitybetween the first electrode and the second electrode and identify theliquid aerosol-forming substrate held in the liquid storage portionindependently of operation the aerosol-generator. This may enable thecontrol system to control operation of the aerosol-generator before theaerosol-generator is operated. This may substantially prevent and/orreduce damage to the aerosol-generator from atomization of an unsuitableliquid aerosol-forming substrate.

The first electrode and the second electrode may be arranged at anysuitable location relative to the liquid storage portion. The firstelectrode and the second electrode may be arranged at or in the liquidstorage portion. The first electrode and the second electrode may bearranged at or on the housing. Where the housing of the liquid storageportion forms a cavity for holding the liquid aerosol-forming substrate,the first electrode and the second electrode may be arranged at or inthe cavity.

The aerosol-generating system may comprise one or more pairs of firstand second electrodes. The aerosol-generating system may comprise two ormore pairs of electrodes arranged such that different portions of theliquid storage portion are arranged between the first and secondelectrodes. Providing multiple pairs of electrodes may improve thereliability of the measurements. The one or more pairs of first andsecond electrodes may comprise part of a sensor.

The electrodes may be any suitable type of electrode. For example,suitable types of electrodes include point electrodes, ring electrodes,plate electrodes or track electrodes. The first electrode and the secondelectrode may be the same type of electrode. The first electrode and thesecond electrode may be different types of electrode.

The electrodes may by any suitable shape. For example, the electrodesmay be: square, rectangular, curved, arcuate, annular, spiral orhelical. The electrodes may be substantially cylindrical. The electrodesmay comprise one or more sections that are substantially linear,non-linear, planar or non-planar. The electrodes may be rigid. This mayenable the electrodes to maintain their shape. The electrodes may beflexible. This may enable the electrodes to conform to the shape of theliquid storage portion. The electrodes may be configured to conform tothe shape of a housing of the liquid storage portion.

The electrodes may have a length, a width, and a thickness. The lengthof the electrodes may be substantially greater than the width of theelectrodes. In other words, the electrodes may be elongate. Thethickness of the electrodes may be substantially less than the lengthand the width of the electrodes. In other words, the electrodes may bethin. Thin electrodes and elongate electrodes may have a larger surfacearea to volume ratio. This may improve the sensitivity of measurements.

The electrodes may comprise any suitable material. The electrodes maycomprise any suitable electrically conductive material. Suitableelectrically conductive materials include metals, alloys, electricallyconductive ceramics and electrically conductive polymers. As used hereinwith respect to example embodiments, an electrically conductive materialrefers to a material having a volume resistivity at 20° C. of less thanabout 1×10⁻⁵ Ωm, or ranging from about 1×10⁻⁵ Ωm to about 1×10⁻⁹ Ωm. Thematerials may include gold and platinum. The electrodes may be coatedwith a passivation layer. The electrodes may comprise or be coated inmaterial that is sufficiently non-reactive so as not to react with orcontaminate the liquid aerosol-forming substrate. The electrodes maycomprise transparent or translucent material. For example, a suitabletransparent material may be Indium Tin Oxide (ITO).

The electrodes may be arranged in any suitable arrangement relative tothe liquid storage portion. The electrodes may be arranged in the liquidstorage portion. The first electrode and the second electrode may bearranged at opposite sides of the liquid storage portion. The firstelectrode and the second electrode may be arranged at opposite ends ofthe liquid storage portion. Where the liquid-storage portion comprises acarrier material, the electrodes may be arranged in contact with thecarrier material. Where the liquid storage portion comprises a housing,at least one of the first and second electrodes may be arranged at or incontact with the housing. The first and second electrodes may besubstantially cylindrical. The first electrode may be arranged tosubstantially surround the second electrode. The first and secondelectrodes may be arranged concentrically about a common axis.

At least one of the first electrode and the second electrode may bearranged on a platform. The platform may comprise electricallyinsulating material. Where the liquid storage portion comprises ahousing, the platform may be separate from the housing. The platform maybe arranged on the housing. The platform may form a portion of thehousing. The platform may comprise the same material as the housing. Theplatform may comprise a different material to the housing.

The platform may comprise any suitable electrically insulating material.For example, suitable electrically insulating materials include glasses,plastics and ceramic materials. As used herein with respect to exampleembodiments, an electrically insulating material refers to a materialhaving a volume resistivity at 20° C. of greater than about 1×10⁶ Ωm, orranging from about 1×10⁹ Ωm to about 1×10²¹ Ωm.

The electrodes may be secured on the platform. The electrodes may besecured on the platform by any suitable means. In at least one exampleembodiment, the electrodes may be secured on the platform by a bondingmaterial, such as an adhesive. The electrodes may be deposited on theplatform by any suitable method of deposition. The electrodes may beetched in the platform.

The second electrode may be spaced apart from the first electrode. Thismay substantially prevent and/or reduce direct contact between the firstelectrode and the second electrode. The spacing between the firstelectrode and the second electrode may be consistent along the length ofthe first electrode and the second electrode. Where the first electrodeand the second electrode are arranged at opposite sides of the liquidstorage portion, the spacing may be about the width of the liquidstorage portion. The spacing between the first electrode and the secondelectrode may range from about 1 μm to about 1 mm, range from about 1 μmto about 500 μm, or range from about 10 μm to about 100 μm.

The second electrode may substantially follow the path of the firstelectrode. This may enable the spacing between the first and secondelectrodes to remain substantially consistent along the length of thefirst and second electrodes. The second electrode may be arrangedsubstantially parallel to the first electrode.

The first electrode and the second electrode may be interdigitated. Thefirst electrode may comprise a plurality of protrusions and interspacesand the second electrode may comprise a plurality of protrusions andinterspaces. The protrusions of the first electrode may extend into theinterspaces of the second electrode and the protrusions of the secondelectrode may extend into the interspaces of the first electrode.Interdigitating the electrodes may minimise the spacing between theelectrodes. This may improve the sensitivity of the measurements.

The protrusions of the first and second electrodes may be substantiallylinear. The protrusions of the first electrode may extend substantiallyin a first direction and the protrusions of the second electrode mayextend substantially in a second direction. The first and secondelectrodes may be arranged with the first direction substantiallyparallel to the second direction. The protrusions may be substantiallynon-linear. The protrusions may be curved or arcuate. For example, asuitable sensor comprising interdigitated electrodes may be of the typeDRP-G-IDEPT10 from DropSens™.

The aerosol-generating system may comprise an aerosol-generatorincluding one or more aerosol-generating elements. The one or moreaerosol-generating elements may comprise one or more heating elements.The one or more aerosol-generating elements may comprise one or morevibratable elements. Where the aerosol-generator comprises one or moreaerosol-generating elements, at least one of the aerosol-generatingelements may comprise one of the electrodes. Forming one of theelectrodes as part of the aerosol-generator may reduce the number ofcomponents required to manufacture the aerosol-generating system.

The control system may comprise electric circuitry. The electriccircuitry may comprise a microprocessor, which may be a programmablemicroprocessor. The electric circuitry may comprise further electroniccomponents. The electric circuitry may be configured to regulate asupply of power to the first electrode and the second electrode.

The control system may be configured to control or regulate a supply ofpower to the first electrode and the second electrode. The controlsystem may be configured to control or regulate a supply of power to theaerosol-generator. A first control system may be configured to controlor regulate the supply of power to the first electrode and the secondelectrode and a second control system may be configured to control orregulate the supply of power to the aerosol-generator.

Power may be supplied substantially continuously to the first electrodeand the second electrode. Power may be supplied to the first electrodeand the second electrode following activation of the system. Power maybe supplied to the first electrode and the second electrode in the formof pulses of electrical current. Power may be supplied to the firstelectrode and the second electrode intermittently, such as on apuff-by-puff basis.

The control system may be configured to supply a measurement signal tothe first electrode and the second electrode. The control system may beconfigured to supply a continuous measurement signal to the firstelectrode and the second electrode. In other words, the control systemmay be configured to supply a direct voltage to the first electrode andthe second electrode. This may require less complex circuitry thansupplying an oscillating measurement signal, such as an alternatingvoltage. Where the control system is configured to supply asubstantially continuous measurement signal, the control system may befurther configured to measure electrical resistance between the firstelectrode and the second electrode.

The control system may be configured to supply an oscillatingmeasurement signal to the first electrode and the second electrode. Inother words, the control system may be configured to supply analternating voltage to the first and second electrodes. The controlsystem may be configured to supply an oscillating measurement signal tothe first electrode and the second electrode at a desired (or,alternatively a predetermined) frequency. The desired (or, alternativelya predetermined) frequency may be any suitable frequency for the controlsystem to measure the electrical quantity between the first electrodeand the second electrode. The desired (or, alternatively apredetermined) frequency may be equal to or less than about 20 MHz, orequal to or less than about 10 MHz. The desired (or, alternatively apredetermined) frequency may range from about 10 kHz to about 10 MHz,range from about 10 kHz to about 1 MHz, or range from about 100 kHz toabout 1 MHz.

Some liquid storage portions comprising different combinations of one ormore carrier materials, liquid aerosol-forming substrates and air mayreact similarly in response to an oscillating measurement signals at aparticular frequency. In at least one example embodiment, on applicationof an oscillating measurement signal at a particular frequency to thefirst electrode and the second electrode, the electrical quantitymeasured for a first liquid storage portion, comprising a first liquidaerosol-forming substrate, may be the same as the electrical quantitymeasured for a second liquid storage portion, comprising a second liquidaerosol-forming substrate, having a different composition to the firstliquid aerosol-forming substrate. Such similar reactions may causeerrors in the identification of the liquid aerosol-forming substrateheld in a liquid storage portion.

Although the reaction of some different liquid storage portions may bethe same in response to an oscillating measurement signal at aparticular frequency, the reaction of these different liquid storageportions may vary in response to an oscillating measurement signal at adifferent frequency. In at least one example embodiment, on theapplication of an oscillating measurement signal at a first frequency,the electrical quantity measured for a first liquid storage portion anda second liquid storage portion may be the same, and on the applicationof an oscillating measurement signal at a second frequency, theelectrical quantity measured for the first liquid storage portion may bedifferent to the electrical signal measured for the second liquidstorage portion.

Similarly, the reaction of different liquid storage portions to theapplication of a continuous measurement signal, such as a directvoltage, may also be the same for certain liquid storage portions anddifferent for other liquid storage portions.

Therefore, in at least one example embodiment, the control system may beconfigured to apply more than one measurement signal to the first andsecond electrode and to identify the liquid aerosol-forming substratebased on measurements of the electrical quantity using differentmeasurement signals. In at least one example embodiment, the controlsystem may be configured to apply oscillating measurement signals to thefirst electrode and the second electrode at more than one frequency. Thecontrol system may be configured to apply a first oscillatingmeasurement signal to the first and second electrodes at a firstfrequency and to apply a second oscillating measurement signal to thefirst and second electrodes at a second frequency. The control systemmay be configured to apply one or more oscillating measurements signalsto the first and second electrodes and a continuous measurement signalto the first and second electrodes. This may improve the accuracy of theidentification of the liquid aerosol-forming substrate held in theliquid storage portion. This may reduce the likelihood of determiningthe wrong identity of the liquid aerosol-forming substrate held in theliquid storage portion. The control system may be configured to identifythe liquid aerosol-forming substrate held in the liquid storage portionwhen the aerosol-generating system is switched on. The control systemmay be configured to identify the liquid aerosol-forming substrate heldin the liquid storage portion periodically at desired (or, alternativelya predetermined) intervals. The control system may be configured toidentify the liquid aerosol-forming substrate held in the liquid storageportion when prompted by an adult vaper.

The aerosol-generating system may comprise a power supply. Theaerosol-generating system may comprise a power supply arranged to supplypower to the control system, the first electrode and the secondelectrode and the aerosol-generator. The aerosol-generator may comprisea single power supply. The aerosol-generator may comprise a first powersupply arranged to supply power to the first electrode and the secondelectrode and a second power supply configured to supply power to theaerosol-generator.

During vaping, liquid aerosol-forming substrate held in the liquidstorage portion is consumed and replaced with air. Liquidaerosol-forming substrates typically have substantially differentelectrical properties to air. Therefore, the amount of liquidaerosol-forming substrate held in the liquid storage portion may affectthe electrical properties of the liquid storage portion. This may affectthe measurement of the electrical quantity between the first electrodeand the second electrode and the identification of the liquidaerosol-forming substrate. The control system may be configured todetermine the amount of liquid aerosol-forming substrate held in theliquid storage portion. The control system may be configured to adjustthe identification of the liquid aerosol-forming substrate based on theamount of liquid aerosol-forming substrate held in the liquid storageportion. In other words, the control system may be configured tocompensate for the amount of liquid aerosol-forming substrate held inthe liquid storage portion.

The control system may be configured to identify the liquidaerosol-forming substrate held in the liquid storage portion whenprompted by an indication for the adult vaper that the liquid storageportion is full. The aerosol-generating system may comprise a switchthat is pressable by an adult vaper to indicate to the control systemthat the aerosol-generating system is full.

The control system may comprise any suitable measuring device configuredto measure the electrical quantity between the first electrode and thesecond electrode. In at least one example embodiment, the control systemmay comprise a bridge circuit configured to measure the electricalquantity between the first electrode and the second electrode. Thebridge circuit may be any suitable bridge circuit known in the art, suchas a Wheatstone bridge or a Wien bridge. The control system may comprisean LCR meter.

The electrical quantity to be measured by the control system may beimpedance. The impedance between the first electrode and the secondelectrode may depend on the composition of the liquid aerosol-formingsubstrate held in the liquid storage portion.

The impedance may be measured directly by the control system. Theimpedance may be calculated. In at least one example embodiment, theimpedance may be calculated from measurements of the magnitude of thevoltage and the current between the electrodes, and measurements of thephase difference between the current and voltage. The identity of theliquid aerosol-forming substrate held in the liquid storage portion maybe determined from the measured or calculated impedance.

The electrical quantity to be measured by the control system may beresistance. The resistance between the first electrode and the secondelectrode may depend on the composition of the liquid aerosol-formingsubstrate held in the liquid storage portion. The resistivity betweenthe first electrode and the second electrode may depend on the liquidaerosol-forming substrate held in the liquid storage portion. Theportion of the liquid storage portion arranged between the firstelectrode and the second electrodes may comprise a resistive load.

The resistance may be measured where the liquid aerosol-formingsubstrate comprises conductive materials.

The resistance may be calculated from measurements of the magnitude ofthe voltage and the current and the phase difference between the voltageand the current. The resistance may be determined from measurements ofthe impedance. The identity of the liquid aerosol-forming substrate heldin the liquid storage portion may be calculated from the measured orcalculated resistance.

The electrical quantity to be measured by the control system may becapacitance where the aerosol-forming substrate comprises dielectricmaterials.

The capacitance between the first electrode and the second electrode maydepend on the composition of the liquid aerosol-forming substrate heldin the liquid storage portion. The permittivity between the firstelectrode and the second electrode may depend on the composition of theliquid aerosol-forming substrate held in the liquid storage portion. Theportion of the liquid storage portion arranged between the firstelectrode and the second electrode may comprise a capacitive load. Thefirst electrode and the second electrode may form a capacitor. The firstelectrode may form a first capacitor plate and the second electrode mayform a second capacitor plate. Liquid aerosol-forming substrate held inthe liquid storage portion may form part of the dielectric of thecapacitor. The capacitive load between the first electrode and thesecond electrode may have a capacitance in the picofarad (pF) range.This may enable fast charging and discharging times of the capacitor,and enable fast measurements of the capacitance.

The capacitance may be measured. In at least one example embodiment, thecontrol system may comprise a capacitance measuring device configured tomeasure charge and discharge times of the capacitor comprising the firstand second electrodes. The control system may comprise a timer circuit,such as a 555 timer circuit, and may be configured to determinecapacitance based on the frequency of the timer circuit output.

The capacitance may be calculated. In at least one example embodiment,the capacitance may be calculated from measurements of the magnitude ofthe voltage and the current between the first and second capacitorplates. The capacitance may be calculated from measurements of theimpedance. The identity of the liquid aerosol-forming substrate held inthe liquid storage portion may be calculated from the measured orcalculated capacitance.

The electrical quantity to be measured by the control system may dependon the size of the first and second electrodes and on the separationbetween the first and second electrodes. In at least one exampleembodiment, capacitance is a function of the separation between thefirst and second capacitor plates and the shape and size of the firstand second capacitor plates. To ensure that a change in the electricalquantity being measured is not the result of a change in the shape orseparation of the first and second electrodes, the first and secondelectrodes may be rigid and secured to a rigid platform or housing. Thecapacitor plates may comprise solid metal plates or thin walled metalsheets attached to a supporting substrate. The supporting substrate maybe arranged between the capacitor plates to form part of the dielectricbetween the capacitor plates. The substrate may be arranged on theoutside of the capacitor plates.

The liquid storage portion may be any suitable shape and size. In atleast one example embodiment, the liquid storage portion may besubstantially cylindrical. The cross-section of the liquid storageportion may, for example, be substantially circular, elliptical, squareor rectangular.

The liquid storage portion may comprise a housing. The housing maycomprise a base and one or more sidewalls extending from the base. Thebase and the one or more sidewalls may be integrally formed. The baseand one or more sidewalls may be distinct elements that are attached orsecured to each other. The housing may be a rigid housing. As usedherein, the term ‘rigid housing’ is used to mean a housing that isself-supporting. The rigid housing of the liquid storage portion mayprovide mechanical support to the aerosol-generator. The liquid storageportion may comprise one or more flexible walls. The flexible walls maybe configured to adapt to the volume of the liquid aerosol-formingsubstrate held in the liquid storage portion. The housing of the liquidstorage portion may comprise any suitable material. The liquid storageportion may comprise substantially fluid impermeable material. Thehousing of the liquid storage portion may comprise a transparent or atranslucent portion, such that liquid aerosol-forming substrate held inthe liquid storage portion may be visible to an adult vaper through thehousing.

The liquid storage portion may be configured such that aerosol-formingsubstrate held in the liquid storage portion is protected from ambientair. The liquid storage portion may be configured such thataerosol-forming substrate stored in the liquid storage portion isprotected from light. This may substantially reduce the risk ofdegradation of the substrate and may maintain a high level of hygiene.

The liquid storage portion may be substantially sealed. The liquidstorage portion may comprise one or more outlets for liquidaerosol-forming substrate held in the liquid storage portion to flowfrom the liquid storage portion to the aerosol-generator. The liquidstorage portion may comprise one or more semi-open inlets. This mayenable ambient air to enter the liquid storage portion. The one or moresemi-open inlets may be semi-permeable membranes or one way valves,permeable to allow ambient air into the liquid storage portion andimpermeable to substantially prevent air and liquid inside the liquidstorage portion from leaving the liquid storage portion. The one or moresemi-open inlets may enable air to pass into the liquid storage portionunder specific conditions.

The liquid storage portion may comprise at least one channel configuredto hold the liquid aerosol-forming substrate. The at least one channelmay be configured such that capillary forces act on the liquidaerosol-forming substrate. The capillary force acting on the liquidaerosol-forming substrate may hold the level of the liquidaerosol-forming substrate substantially perpendicular to at least one ofthe sidewalls of the liquid storage portion and the first and secondelectrodes. One dimension of the channel may be less than a desired (or,alternatively a predetermined) value, such that capillary forces act onliquid aerosol-forming substrate held in the channel. The dimension ofthe one or more channels may be the width of the one or more channel.The desired (or, alternatively a predetermined) value may be below about3 mm, below about 2 mm, below about 0.5 mm, or below about 0.25 mm.

The liquid storage portion may comprise aerosol-forming substrate heldin the liquid storage portion. As used herein with reference to theexample embodiments, an aerosol-forming substrate is a substrate capableof releasing volatile compounds that can form an aerosol. Volatilecompounds may be released by heating the aerosol-forming substrate.Volatile compounds may be released by moving the aerosol-formingsubstrate through passages of a vibratable element.

The aerosol-forming substrate may be liquid. The aerosol-formingsubstrate may be liquid at room temperature. The liquid aerosol-formingsubstrate may comprise both liquid and solid components. Theaerosol-forming substrate may comprise nicotine. The nicotine containingliquid aerosol-forming substrate may be a nicotine salt matrix. Theaerosol-forming substrate may comprise plant-based material. Theaerosol-forming substrate may comprise tobacco. The aerosol-formingsubstrate may comprise a tobacco-containing material containing volatiletobacco flavor compounds, which are released from the aerosol-formingsubstrate upon heating. The aerosol-forming substrate may comprisehomogenized tobacco material. The aerosol-forming substrate may comprisea non-tobacco-containing material. The aerosol-forming substrate maycomprise homogenized plant-based material.

The liquid aerosol-forming substrate may comprise at least oneaerosol-former. An aerosol-former is any suitable known compound ormixture of compounds that, during vaping, facilitates formation of adense and stable aerosol and that is substantially resistant to thermaldegradation at the temperature of operation of the system. Suitableaerosol-formers are well known in the art and include, but are notlimited to: polyhydric alcohols, such as triethylene glycol,1,3-butanediol and glycerine; esters of polyhydric alcohols, such asglycerol mono-, di- or triacetate; and aliphatic esters of mono-, di- orpolycarboxylic acids, such as dimethyl dodecanedioate and dimethyltetradecanedioate. Aerosol formers may be polyhydric alcohols ormixtures thereof, such as triethylene glycol, 1,3-butanediol andglycerine. The liquid aerosol-forming substrate may comprise otheradditives and ingredients, such as flavorants.

The liquid aerosol-forming substrate may comprise water, solvents,ethanol, plant extracts and natural or artificial flavors. The liquidaerosol-forming substrate may comprise one or more aerosol formers.Examples of suitable aerosol formers include glycerine and propyleneglycol.

The liquid aerosol-forming substrate may comprise nicotine and at leastone aerosol former. The aerosol former may be glycerine. Theaerosol-former may be propylene glycol. The aerosol former may compriseboth glycerine and propylene glycol. The liquid aerosol-formingsubstrate may have a nicotine concentration ranging from about 0.5% toabout 10%. In at least one example embodiment, the nicotineconcentration is about 2%.

The liquid aerosol-forming substrate may contain a mixture of dielectricmaterials, each with a separate dielectric constant (k). The mainconstituents of a liquid aerosol-forming substrate at room temperature,about 20° C., may include: glycerine (k˜42), propylene glycol (k˜32),water (k˜80), air (k˜1), nicotine and flavorants. Where the liquidaerosol-forming substrate forms a dielectric material, the electricalquantity to be measured by the control system may be capacitance.

The liquid aerosol-forming substrate may comprise a mixture ofelectrically conductive materials. Where the liquid aerosol-formingsubstrate forms an electrically conductive material, the electricalquantity to be measured by the control system may be resistance.

The liquid storage portion may comprise a carrier material within thehousing. The carrier material is configured to hold the liquidaerosol-forming substrate. The liquid aerosol-forming substrate may beadsorbed or otherwise loaded onto the carrier material. Liquidaerosol-forming substrate absorbed in the material may spread orpermeate through the carrier material, and changes in the saturation ofthe carrier material affect the entire body of carrier material. Thismay enable first and second electrodes arranged in contact with aportion of the carrier material to sense changes in the electricalquantity of the entire body of carrier material. This may enable thecontrol system to measure the electrical quantity of the entire liquidstorage portion.

The carrier material may be made from any suitable absorbent body ofmaterial, for example, a foamed metal or plastics material,polypropylene, terylene, nylon fibres or ceramic. The aerosol-formingsubstrate may be retained in the carrier material prior to vaping of theaerosol-generating system. The aerosol-forming substrate may be releasedinto the carrier material during vaping. The aerosol-forming substratemay be released into the carrier material immediately prior to vaping.In at least one example embodiment, the liquid aerosol-forming substratemay be provided in a capsule. The shell of the capsule may melt uponheating by the heating element and releases the liquid aerosol-formingsubstrate into the carrier material. The capsule may contain a solid incombination with the liquid.

The liquid aerosol-forming substrate may be held in a capillarymaterial. A capillary material is a material that actively conveysliquid from one end of the material to another. The capillary materialmay draw liquid aerosol-forming substrate to a specific location in theliquid storage portion, regardless of the orientation of the liquidstorage portion. This may facilitate arrangement of the first and secondelectrodes for accurate and reliable determination of the identity ofthe liquid aerosol-forming substrate held in the liquid storage portion.

The capillary material may be configured to convey the aerosol-formingsubstrate to the aerosol-generator. The capillary material may beconfigured to convey the aerosol-forming substrate to the first andsecond electrodes. The capillary material may have a fibrous structure.The capillary material may have a spongy structure. The capillarymaterial may comprise a bundle of capillaries. The capillary materialmay comprise a plurality of fibers. The capillary material may comprisea plurality of threads. The capillary material may comprise fine boretubes. The fibers, threads or fine-bore tubes may be generally alignedto convey liquid to an atomizer. The capillary material may comprise acombination of fibers, threads and fine-bore tubes. The capillarymaterial may comprise sponge-like material. The capillary material maycomprise foam-like material. The structure of the capillary material mayform a plurality of small bores or tubes, through which the liquid canbe transported by capillary action.

The capillary material may comprise any suitable material or combinationof materials. Examples of suitable materials are a sponge or foammaterial, ceramic- or graphite-based materials in the form of fibers orsintered powders, foamed metal or plastics materials, a fibrousmaterial, for example made of spun or extruded fibres, such as celluloseacetate, polyester, or bonded polyolefin, polyethylene, terylene orpolypropylene fibers, nylon fibers or ceramic. The capillary materialmay have any suitable capillarity and porosity so as to be used withdifferent liquid physical properties. The liquid aerosol-formingsubstrate has physical properties, including but not limited toviscosity, surface tension, density, thermal conductivity, boiling pointand vapour pressure, which allow the liquid to be transported throughthe capillary material by capillary action.

The aerosol-generator may be configured to receive aerosol-formingsubstrate from the liquid storage portion. The aerosol-generator may bean atomizer and/or a vaporizer. The aerosol-generator may comprise oneor more aerosol-generating elements. The aerosol-generator may beconfigured to vaporize received aerosol-forming substrate using heat.The aerosol-generator may comprise a heating element configured tovaporize received liquid aerosol-forming substrate. Theaerosol-generator may be configured to atomize received aerosol-formingsubstrate using ultrasonic vibrations. The aerosol-generator maycomprise an ultrasonic transducer. The one or more aerosol-generatingelements may comprise one or more vibratable elements.

The aerosol-generator may comprise a heating element configured to heatthe aerosol-forming substrate. The heating element may comprise one ormore heating elements. The one or more heating elements may be arrangedappropriately so as to most effectively heat received aerosol-formingsubstrate. The one or more heating elements may be configured to heatthe aerosol-forming substrate primarily by conduction. The one or moreheating elements may be substantially in direct contact with theaerosol-forming substrate. The one or more heating elements may bearranged to transfer heat to the aerosol-forming substrate via one ormore heat conductive elements. The one or more heating elements may bearranged to transfer heat to ambient air drawn through theaerosol-generating system during vaping, which may heat theaerosol-forming substrate by convection. The one or more heatingelements may be arranged to heat the ambient air before it is drawnthrough the aerosol-forming substrate. The one or more heating elementsmay be arranged to heat the ambient air after it is drawn through theaerosol-forming substrate.

The heating elements may be an electric heater. The electric heater maycomprise one or more electric heating elements. The one or more electricheating elements may comprise an electrically resistive material.Suitable electrically resistive materials may include: semiconductorssuch as doped ceramics, electrically “conductive” ceramics (such as, forexample, molybdenum disilicide), carbon, graphite, metals, metal alloysand composite materials made of a ceramic material and a metallicmaterial.

The one or more electric heating elements may take any suitable form. Inat least one example embodiment, the one or more electric heatingelements may take the form of one or more heating blades. The one ormore electric heating elements may take the form of a casing orsubstrate having different electro-conductive portions, or one or moreelectrically resistive metallic tube.

The liquid storage portion may incorporate one or more disposableheating elements. The one or more electric heating elements may compriseone or more heating needles or rods that run through the aerosol-formingsubstrate. The one or more electric heating elements may comprise one ormore flexible sheets of material. The electric heating element maycomprise one or more heating wires or filaments, for examplenickel-chromium (Ni—Cr), platinum, tungsten or alloy wires, or heatingplates. The one or more heating elements may be deposited in or on arigid carrier material.

The one or more heating elements may comprise one or more heat sinks orheat reservoirs. The one or more heat sinks or heat reservoirs maycomprise a material capable of absorbing and storing heat andsubsequently releasing the heat over time to heat the aerosol-formingsubstrate.

The heating elements may be substantially flat to allow forstraightforward manufacture. As used herein, the term ‘substantiallyflat’ means formed in a single plane and not wrapped around or otherwiseconfirmed to fit a curved or other non-planar shape. A flat heatingelements may be easily handled during manufacture and provide for arobust construction.

The heating elements may be of the type described in EP-B1-2493342, theentire content of which is incorporated herein by reference thereto. Inat least one example embodiment, the heating elements may comprise oneor more electrically conductive tracks on an electrically insulatingsubstrate. The electrically insulating substrate may comprise anysuitable material, and may be a material that is able to tolerate hightemperatures (in excess of 300° C.) and rapid temperature changes. Anexample of a suitable material is a polyimide film, such as Kapton®.

The heating elements may be configured to heat a small amount of liquidaerosol-forming substrate at a time. The heating elements configured toheat a small amount of liquid aerosol-forming substrate at a time mayinclude, for example, a liquid passageway in communication with theliquid aerosol-forming substrate. The liquid aerosol-forming substratemay be forced into the liquid passageway by capillary force. The atleast one heater may be arranged such that during vaping, only the smallamount of liquid aerosol-forming substrate within the liquid passageway,and not the liquid within the housing, is heated. The heating elementsmay comprise a coil substantially surrounding at least a portion of aliquid passageway.

The heating element may comprise an inductive heating element. Inductiveheating elements are described in more detail below, in relation to thecartridge.

The aerosol-generator may comprise one or more vibratable elements andone or more actuators arranged to excite vibrations in the one or morevibratable elements. The one or more vibratable elements may comprise aplurality of passages through which aerosol-forming substrate may passand become atomized. The one or more actuators may comprise one or morepiezoelectric transducers.

The aerosol-generator may comprise one or more capillary wicks forconveying liquid aerosol-forming substrate held in the liquid storageportion to the one or more elements of the aerosol-generator. The liquidaerosol-forming substrate may have physical properties, includingviscosity, which allow the liquid to be transported through the one ormore capillary wicks by capillary action. The one or more capillarywicks may have any of the properties of structures described aboverelating to the capillary material.

The one or more capillary wicks may be arranged to contact liquid heldin the liquid storage portion. The one or more capillary wicks mayextend into the liquid storage portion. In this case, during vaping,liquid may be transferred from the liquid storage portion to the one ormore elements of the aerosol-generator by capillary action in the one ormore capillary wicks. The one or more capillary wicks may have a firstend and a second end. The first end may extend into the liquid storageportion to draw liquid aerosol-forming substrate held in the liquidstorage portion into the aerosol generator. The second end may extendinto an air passage of the aerosol-generating system. The second end maycomprise one or more aerosol-generating elements. The first end and thesecond end may extend into the liquid storage portion. One or moreaerosol-generating elements may be arranged at a central portion of thewick between the first and second ends. During vaping, when the one ormore aerosol-generating elements are activated, the liquidaerosol-forming substrate in the one or more capillary wicks is atomizedand/or vaporized at and around the one or more aerosol-generatingelements.

The aerosol-generator may comprise one or more heating wires orfilaments encircling a portion of one or more capillary wicks. Theheating wire or filament may support the encircled portion of the one ormore capillary wicks.

During vaping, atomized aerosol-forming substrate may be mixed with andcarried in air flow through an air passage of the aerosol-generatingsystem. The capillary properties of the one or more capillary wicks,combined with the properties of the liquid substrate, may ensure that,during vaping when there is sufficient aerosol-forming substrate, thewick is always wet with liquid aerosol-forming substrate in the area ofthe aerosol-generator.

The aerosol-generating system may comprise one or more power supplies.The power supply may be a battery. The battery may be a Lithium basedbattery, for example a Lithium-Cobalt, a Lithium-Iron-Phosphate, aLithium Titanate or a Lithium-Polymer battery. The battery may be aNickel-metal hydride battery or a Nickel cadmium battery. The powersupply may be another form of charge storage device such as a capacitor.The power supply may require recharging and be configured for manycycles of charge and discharge. The power supply may have a capacitythat allows for the storage of enough energy for one or more vapingexperiences; for example, the power supply may have sufficient capacityto allow for the continuous generation of aerosol for a period of aroundsix minutes, corresponding to the typical time taken to smoke aconventional cigarette, or for a period that is a multiple of sixminutes. In another example embodiment, the power supply may havesufficient capacity to allow for a desired (or, alternatively apredetermined) number of puffs or discrete activations of the heatingelement and actuator.

The aerosol-generating system may comprise a control system configuredto operate the aerosol-generator. The control system configured tooperate the aerosol-generator may be the control system configured toidentify the liquid aerosol-forming substrate held in the liquid storageportion. The control system configured to operate the aerosol-generatormay be distinct of the control system configured to identify the liquidaerosol-forming substrate held in the liquid storage portion. Thecontrol system configured to operate the aerosol-generator may comprisesimilar components to the control system configured to identify theliquid held in the liquid storage portion.

The aerosol-generating system may comprise a temperature sensor incommunication with the control system. The temperature sensor may beadjacent to the liquid storage portion. The temperature sensor may be athermocouple. At least one element of the aerosol-generator may be usedby the control system to provide information relating to thetemperature. The temperature dependent resistive properties of the atleast one element may be known and used to determine the temperature ofthe at least one element in a manner known to the skilled person. Thecontrol system may be configured to account or compensate for the effectof temperature on the electrical load between the first electrode andthe second electrode using measurements of temperature from thetemperature sensor.

The aerosol-generating system may comprise a puff detector incommunication with the control electronics. The puff detector may beconfigured to detect when an adult vaper draws on the mouthpiece. Thecontrol electronics may be configured to control power to theaerosol-generator in dependence on the input from the puff detector.

The control system may comprise a tilt sensor. The tilt sensor may beconfigured to sense the orientation of the liquid storage portion. Theaerosol-generating system may comprise a control system configured toreceive sensed orientation information from the tilt sensor and todetermine the orientation of the liquid storage portion. By determiningthe orientation of the liquid storage portion, the control system may beconfigured to determine whether the liquid aerosol-forming substrateheld in the liquid storage portion is substantially perpendicular to thefirst electrode and the second electrode. The control system may beconfigured to identify the liquid aerosol-forming substrate held in theliquid storage portion when the liquid aerosol-forming substrate held inthe liquid storage portion is substantially perpendicular to the firstand second electrodes, such as when the liquid storage portion isdetermined to be upright.

The liquid aerosol-forming substrate may be subject to gravitational andacceleration forces that move the liquid aerosol-forming substrate todifferent sections of the liquid storage portion. Provided that theentire liquid storage portion is between the first and secondelectrodes, the measurement of the electrical quantity should not beaffected.

The aerosol-generating system may comprise an input, such as a switch orbutton. This enables the adult vaper to turn the system on. The switchor button may activate the aerosol-generator. The switch or button mayinitiate aerosol generation. The switch or button may prepare thecontrol electronics to await input from the puff detector.

The aerosol-generating system may comprise at least one indicator, forindicating the determined liquid aerosol-forming substrate identity toan adult vaper. The indicator may comprise one or more of lights, suchas light emitting diodes (LEDs), a display, such as an LCD display, anda loudspeaker or buzzer. The control system may be configured toindicate the determined liquid aerosol-forming substrate identity to anadult vaper with the indicator. The control system may be configured tolight one or more of the lights depending on the determined strength ofliquid aerosol-forming substrate, display a type or strength of liquidaerosol-forming substrate on the display or emit sounds via theloudspeaker or buzzer to indicate determination of an authorized orunauthorized liquid aerosol-forming substrate.

The aerosol-generating system may comprise a housing. The housing may beelongate. The housing may comprise any suitable material or combinationof materials. Examples of suitable materials include metals, alloys,plastics or composite materials containing one or more of thosematerials, or thermoplastics that are suitable for food orpharmaceutical applications, for example polypropylene,polyetheretherketone (PEEK) and polyethylene. The material may be lightand non-brittle.

The housing may comprise a cavity for receiving the power supply. Thehousing may comprise a mouthpiece. The mouthpiece may comprise at leastone air inlet and at least one air outlet. The mouthpiece may comprisemore than one air inlet. One or more of the air inlets may reduce thetemperature of the aerosol before it is delivered to an adult vaper andmay reduce the concentration of the aerosol before it is delivered to anadult vaper.

The aerosol-generating system may be portable. The aerosol-generatingsystem may have a size comparable to a cigar or a cigarette. Theaerosol-generating system may have a total length ranging from about 30mm to about 150 mm. The aerosol-generating system may have an externaldiameter ranging from about 5 mm to about 30 mm.

The aerosol generating system may be an electrically operated vapingsystem. The aerosol-generating system may be an electronic cigarette oran electronic cigar.

The aerosol-generating system may comprise a main unit and a cartridge.The cartridge comprises the liquid storage portion for holding theliquid aerosol-forming substrate. The main unit may be configured toremovably receive the cartridge. The first electrode and the secondelectrode may be arranged such that a portion of the liquid storageportion of the cartridge is between the first electrode and the secondelectrode when the cartridge is received by the main unit.

The main unit may comprise one or more power supplies. The main unit maycomprise the aerosol-generator.

The cartridge may comprise the aerosol-generator. Where the cartridgecomprises the aerosol-generator, the cartridge may be referred to as a‘cartomizer’.

The aerosol-generating system may comprise an aerosol-generatingcomponent comprising the aerosol-generator. The aerosol-generatingcomponent may be separate of the main unit and the cartridge. Theaerosol-generating component may be removably receivable by at least oneof the main unit and the cartridge.

The main unit may comprise the first electrode and the second electrode.The cartridge may comprise the first electrode and the second electrode.The main unit may comprise one of the first electrode and the secondelectrode. The cartridge may comprise one of the first electrode and thesecond electrode. Arranging one of the first electrode and the secondelectrode on the main unit and arranging the other of the firstelectrode and the second electrode on the cartridge may enableidentification of the cartridge. In other words, the presence or absenceof an electrode on the cartridge may be used to verify whether thecartridge received by the main unit is a genuine or authentic cartridgefrom the manufacturer of the main unit. The type of electrode ormeasurements between the electrode of the main unit and the electrode ofthe cartridge may also be used to identify the type of cartridgereceived by the main unit or the type of liquid aerosol-formingsubstrate held in the liquid storage portion of the cartridge. Thecontrol system may be configured to determine the presence or absence ofan electrode in the cartridge. The control system may be configured todetermine the identity the cartridge based on the presence or absence ofan electrode in the cartridge. The control system may also be configuredto determine whether the cartridge has been correctly received by themain unit based on the presence or absence of an electrode in thecartridge.

The control system may be configured to identify the cartridge based onmeasured electrical quantity information between the first electrode andthe second electrode. In other words, the control system may beconfigured to recognise an authentic cartridge. This may enable theaerosol-generating system or adult vaper to control operation of theaerosol-generating system to optimize atomization and/or vaporization ofthe liquid aerosol-forming substrate. This may enable a main unit toreduce and/or substantially prevent counterfeit cartridges from beingused with the main unit.

Identification of a cartridge or a liquid aerosol-forming substrate heldin a liquid storage portion of a cartridge may be straightforward forbrand new cartridges, where the amount of liquid aerosol-formingsubstrate held in the liquid storage portion may be known. The controlsystem may be configured to determine when a new cartridge is receivedby the main unit. The main unit may comprise a switch configured toactivate on receipt of a cartridge by the main unit, or to be activatedby an adult vaper on receipt of a new cartridge by the main unit.

The aerosol-generator may comprise heating elements substantially asdescribed above. The heating elements may be inductive heating elements,such that no electrical contacts are formed between the cartridge andthe main unit. The main unit may comprise an inductor coil and a powersupply configured to provide high frequency oscillating current to theinductor coil. The cartridge may comprise a susceptor element positionedto heat the aerosol-forming substrate. As used herein, a high frequencyoscillating current means an oscillating current having a frequency ofbetween 10 kHz and 20 MHz.

The cartridge may be removably coupled to the main unit. The cartridgemay be removed from the main unit when the aerosol-forming substrate hasbeen consumed. The cartridge may be disposable. The cartridge may bereusable. The cartridge may be refillable with liquid aerosol-formingsubstrate. The cartridge may be replaceable in the main unit. The mainunit may be reusable.

The cartridge may be manufactured at low cost, in a reliable andrepeatable fashion. As used herein, the term ‘removably coupled’ is usedto mean that the cartridge and the main unit can be coupled anduncoupled from one another without significantly damaging either themain unit or cartridge.

The cartridge may have a simple design. The cartridge may have a housingwithin which a liquid aerosol-forming substrate is held. The cartridgehousing may be a rigid housing. The housing may comprise a material thatis impermeable to liquid.

The cartridge may comprise a lid. The lid may be peelable beforecoupling the cartridge to the main unit. The lid may be piercable.

The main unit may comprise a cavity for receiving the cartridge. Themain unit may comprise a cavity for receiving the power supply.

The main unit may comprise the aerosol-generator. The main unit maycomprise one or more control systems of the aerosol-generating system.The main unit may comprise the power supply. The power supply may beremovably coupled to the main unit.

The main unit may comprise the mouthpiece. The mouthpiece may compriseat least one air inlet and at least one air outlet. The mouthpiece maycomprise more than one air inlet.

The main unit may comprise a piercing element for piercing the lid ofthe cartridge. The mouthpiece may comprise the piercing element. Themouthpiece may comprise at least one first conduit extending between theat least one air inlet and a distal end of the piercing element. Themouthpiece may comprise at least one second conduit extending between adistal end of the piercing element and the at least one air outlet. Themouthpiece may be arranged such that during vaping, when an adult vaperdraws on the mouthpiece, air flows along an air passage extending fromthe at least one air inlet, through the at least one first conduit,through a portion of the cartridge, through the at least one secondconduit and exits the at least one outlet. This may improve airflowthrough the main unit and enable the aerosol to be delivered to theadult vaper more easily.

During vaping, an adult vaper may insert a cartridge as described hereininto the cavity of a main unit as described herein. The adult vaper mayattach the mouthpiece to the main body of the main unit, which maypierce the cartridge with the piercing portion. The adult vaper mayactivate the main unit by pressing the switch or the button. The adultvaper may draw on the mouthpiece to draw air into the main unit throughthe one or more air inlets. The air may pass over a portion of theaerosol-generator, entraining atomized and/or vaporized aerosol-formingsubstrate, and exit the main unit through the air outlet in themouthpiece to be inhaled by the adult vaper.

A kit of parts may be provided, comprising a cartridge, a main unit,substantially as described above. An aerosol-generating system accordingto at least one example embodiment may be provided by assembling thecartridge, the aerosol-generator and the main unit. The components ofthe kit of parts may be removably connected. The components of the kitof parts may be interchangeable. Components of the kit of parts may bedisposable. Components of the kit of parts may be reusable.

There may be provided a main unit for an aerosol-generating systemaccording to at least one example embodiment. The main unit may comprisethe control system and at least one of the first electrode and thesecond electrode.

There may be provided a cartridge for an aerosol-generating systemaccording to at least one example embodiment. The cartridge maycomprise: the liquid storage portion; and at least one of the firstelectrode and the second electrode. The cartridge may comprise a housingfor holding a liquid aerosol-forming substrate in the liquid storageportion. The cartridge may comprise aerosol-generator configured toreceive liquid aerosol-forming substrate from the liquid storageportion.

According to at least one example embodiment, a method of identifyingliquid aerosol-forming substrate held in a liquid-storage portion of anaerosol-generating system comprises: holding a liquid aerosol-formingsubstrate in a liquid storage portion of an aerosol-generating system;arranging at least a portion of the liquid storage portion between afirst electrode and a second electrode, the portion of the liquidstorage portion between the first electrode and the second electrodeholding liquid aerosol-forming substrate when liquid aerosol-formingsubstrate is held in the liquid storage portion; measuring an electricalquantity between the first electrode and the second electrode; andidentifying the liquid aerosol-forming substrate held in the liquidstorage portion based on the measured electrical quantity information.

Features such as the liquid storage portion and the first electrode andthe second electrode may be the same as those described in relation tothe example embodiments described above.

The identifying the liquid aerosol-forming substrate held in the liquidstorage portion may comprise comparing the measured electrical quantityinformation to reference electrical quantity information. The referenceelectrical quantity information may be electrical quantity informationpreviously measured by the control system. The reference electricalquantity information may be stored in a memory of the aerosol-generatingsystem. The reference electrical quantity information may be stored in alookup table.

The reference electrical quantity information may be measured by thecontrol system in a calibration procedure. The calibration procedure maybe performed to populate the lookup table. In the calibration procedure,the liquid storage portion may be loaded with desired (or, alternativelya predetermined) liquid aerosol-forming substrates. The electricalquantity between the first electrode and the second electrode may bemeasured when the liquid storage portion is loaded with the known liquidaerosol-forming substrates. The measured electrical quantity informationmay be stored in a lookup table and associated in the lookup table withthe known identity of the liquid aerosol-forming substrate held in theliquid storage portion at the time of the measurement.

The calibration procedure may be performed in the factory before theaerosol-generating system is distributed. The calibration procedure maybe performed by an adult vaper before the first vaping of theaerosol-generating system.

A method of controlling operation of aerosol-generator of anaerosol-generating system may comprise: holding a liquid aerosol-formingsubstrate in a liquid storage portion of an aerosol-generating system;arranging at least a portion of the liquid storage portion between afirst electrode and a second electrode, the portion of the liquidstorage portion between the first electrode and the second electrodeholding liquid aerosol-forming substrate when liquid aerosol-formingsubstrate is held in the liquid storage portion; measuring an electricalquantity between the first electrode and the second electrode;identifying the liquid aerosol-forming substrate held in the liquidstorage portion based on the measured electrical quantity information;and controlling operation of aerosol-generator of the aerosol-generatingsystem based on the determined identity of the liquid aerosol-formingsubstrate held in the liquid storage portion.

Features described in relation to one example embodiment may also beapplicable to other example embodiments. Features described in relationto the method may be applicable to the aerosol-generating system andfeatures corresponding to the aerosol-generating system may beapplicable to the method.

FIG. 1 is a schematic illustration of an aerosol-generating system. FIG.1 is schematic in nature, and the components shown are not necessarilyto scale either individually or relative to one another. Theaerosol-generating system comprises a main unit 100, which is preferablyreusable, in cooperation with a cartridge 200, which is preferablydisposable. The aerosol-generating system shown in FIG. 1 is anelectrically operated vaping system.

The main unit 100 comprises a main housing 101. The housing issubstantially cylindrical and has a longitudinal length of about 100 mmand an external diameter of about 20 mm, comparable to a cigar. The mainunit 100 comprises an electric power supply in the form of a lithium ionphosphate battery 102 and a control system in the form of controlelectronics 104. The main housing 101 also defines a cavity 112 intowhich the cartridge 200 is received.

The main unit 100 also includes a mouthpiece portion 120 including anoutlet 124. The mouthpiece portion is connected to the main housing 101by a hinged connection in this example but any kind of connection may beused, such as a snap fitting or a screw fitting. One or more air inlets122 are provided between the mouthpiece portion 120 and the main body101 when the mouthpiece portion is in a closed position, as shown inFIG. 1.

Within the mouthpiece portion is a flat spiral inductor coil 110. Thecoil 110 is formed by stamping or cutting a spiral coil from a sheet ofcopper. The coil 110 is positioned between the air inlets 122 and theair outlet 124 so that air drawn through the inlets 122 to the outlet124 passes through the coil.

The cartridge 200 (shown in schematic form in FIG. 1) comprises a rigidhousing 204 defining a liquid storage portion 201. The liquid storageportion 201 contains a liquid aerosol-forming substrate (not shown). Thehousing 204 of the cartridge 200 is fluid impermeable but has an openend covered by a permeable susceptor element 210. The permeablesusceptor element 210 comprises a ferrite mesh, comprising a ferritesteel. The aerosol-forming substrate can form a meniscus in theinterstices of the mesh. When the cartridge 200 is engaged with the mainunit and is received in the cavity 112, the susceptor element 210 ispositioned adjacent the flat spiral coil 110. The cartridge 200 mayinclude keying features to ensure that it cannot be inserted into themain unit upside-down.

During vaping, an adult vaper puffs on the mouthpiece portion 120 todraw air though the air inlets 122 into the mouthpiece portion 120 andout of the outlet 124. The main unit includes a puff sensor 106 in theform of a microphone, as part of the control electronics 104. A smallair flow is drawn through sensor inlet 121 past the microphone 106 andup into the mouthpiece portion 120 when an adult vaper puffs on themouthpiece portion. When a puff is detected, the control electronicsprovide a high frequency oscillating current to the coil 110. Thisgenerates an oscillating magnetic field as shown in dotted lines inFIG. 1. An LED 108 is also activated to indicate that the main unit isactivated. The oscillating magnetic field passes through the susceptorelement, inducing eddy currents in the susceptor element. The susceptorelement heats up as a result of Joule heating and as a result ofhysteresis losses, reaching a temperature sufficient to vaporize theaerosol-forming substrate close to the susceptor element. The vaporizedaerosol-forming substrate is entrained in the air flowing from the airinlets to the air outlet and cools to form an aerosol within themouthpiece portion. The control electronics supplies the oscillatingcurrent to the coil for a desired (or, alternatively a predetermined)duration, in this example five seconds, after detection of a puff andthen switches the current off until a new puff is detected.

The cartridge 200 has generally cylindrical shape and the susceptorelement spans a circular open end of the cartridge housing. It will beappreciated that other configurations are possible. In at least oneexample embodiment, the susceptor element may be a strip of steel mesh220 that spans a rectangular opening in the cartridge housing 204.

In at least one example embodiment, as shown in FIG. 1, theaerosol-generating system may rely on inductive heating. Furtherexamples of suitable inductive heating elements and explanation of theoperation of inductive heating systems are described in WO 2015/177046A1, the entire content of which is incorporated herein by referencethereto.

It will be appreciated that the aerosol-generating system may compriseother types of aerosol-generator. In at least one example embodiment,the aerosol-generator may comprise other aerosol-generator configured toatomise the liquid aerosol-forming substrate by heat. Theaerosol-generator may comprise one or more resistive heating elements.The aerosol-generator may also comprise aerosol-generator configured toatomise the liquid aerosol-forming substrate by vibration. Theaerosol-generator may comprise one or more vibratable elements andactuators.

Several examples of cartridges suitable for main units ofaerosol-generating systems, such as the main unit shown in FIG. 1, areshown in FIGS. 2 to 12. The cartridges shown in FIGS. 2 to 12 compriseliquid storage portions and electrode arrangements according to thepresent invention.

The cartridge 300 shown in FIG. 2 comprises a substantially cylindricalhousing 301, having a closed end and a substantially open end. Thehousing is rigid and substantially fluid impermeable, and defines aliquid storage portion that is configured to hold liquid aerosol-formingsubstrate (not shown) either freely or held in a carrier material.

Aerosol-generating elements 302 are provided over the open end of thehousing 301. In at least one example embodiment, the aerosol-generatingelements comprise a ferrite mesh susceptor. A sensor 303 is on an innersurface of the housing 301, within the liquid storage portion. Thesensor comprises a first electrode 304 and a second electrode 305. Thefirst and second electrodes 304, 305 are substantially identical andcomprise arcuate metal plates at opposite sides of housing 301. Eachelectrode 304, 305 substantially circumscribes about half thecircumference of the inner surface of the housing 301 and extendssubstantially the length of the housing 301, from the open end to theclosed end. The electrodes 304, 305 are on the housing with a gapbetween the sides of the plates, to ensure that the plates 304, 305 arenot in an electrically conductive relationship. This arrangement enablesthe sensor 303 to sense electrical quantities of the entire liquidstorage portion.

Electrical contacts (not shown) extend through the housing, from theouter surface to the inner surface of each of the plates. When thecartridge 300 is received in a cavity of a main unit, the contacts ofthe cartridge 300 abut complimentary contacts in the cavity of the mainunit to electrically connect the sensor 303 to a power supply and acontrol system of the main unit.

The cartridge 310 shown in FIG. 3 has a substantially similarconstruction to the cartridge 300 shown in FIG. 2. The cartridge 310comprises a substantially cylindrical housing 311 defining a liquidstorage portion, and an aerosol-generating element 312 over an open end.The cartridge 300 comprises a sensor 313 around at an outer surface ofthe liquid storage portion. The sensor 313 comprises a first electrode314 and a second electrode 315. The first and second electrodes 314, 315are substantially identical and comprise copper rings circumscribing theouter surface of the housing 311. The first electrode 314, 315 isarranged towards the open end of the housing 311 and the secondelectrode 315 is arranged towards the closed end so that the sensor 313is configured to sense electrical quantities of the entire liquidstorage portion.

The cartridge 320 shown in FIG. 4 has a substantially similarconstruction to the cartridge 310 shown in FIG. 3. The cartridge 320comprises a substantially cylindrical housing 321, having an open endand a closed end, and an aerosol-generating element 322 arranged overthe open end. The cartridge 320 comprises a sensor 323 comprising afirst electrode 324 comprising a ring electrode at an inner surface ofthe housing 321, and a second electrode comprising theaerosol-generating element 322.

The cartridge 330 shown in FIG. 5 has a substantially similarconstruction to the cartridges 300, 310 and 320 shown in FIGS. 2, 3 and4. The cartridge 330 comprises a substantially cylindrical housing 331,having an open end and a closed end, and an aerosol-generating element332 over the open end. The cartridge 330 comprises a sensor 333 at aninner surface of the housing 321. The sensor 333 comprises a firstelectrode 334 and a second electrode 335. The first and secondelectrodes 334, 335 are point electrodes extending through opposingsides of the housing 331 at the same position along the length of thehousing 331. This minimizes and/or reduces the distance between theelectrodes and may improve the sensitivity of the sensor 333. Wherecarrier material is provided in the liquid storage portion, the pointelectrodes 334, 335 may be in contact with the carrier material. Liquidaerosol-forming substrate held in the liquid storage portion permeatesthrough the carrier material. A change in the amount of liquidaerosol-forming substrate held in the liquid storage portion affects thesaturation of the carrier material, and changes the electricalquantities of the carrier material. This enables the point electrodes334, 335 to sense electrical quantities of the entire liquid storageportion.

The cartridge 340 shown in FIG. 6 has a substantially similarconstruction to the cartridges 300, 310, 320 and 330 shown in FIGS. 2,3, 4 and 5. The cartridge 340 comprises a substantially cylindricalhousing 341, having an open end and a closed end, and anaerosol-generating element 342 over the open end. The cartridge 340comprises a sensor 343 at an inner surface of the housing 341. Thesensor 343 comprises first and second electrodes (not shown) on aplatform. The platform comprises an electrically insulating polymersheet, having a similar size and shape to one of the electrodes 304, 305of the cartridge 300 shown in FIG. 2. The platform is adhered to theinner surface of the housing 343 and is sufficiently flexible to conformto the shape of the housing 343.

In at least one example embodiment, the first and second electrodes maybe on a platform, such as the platform of the sensor 343 as shown inFIG. 7. The sensor 343′ comprises a first electrode 344′ and a secondelectrode 345′ that are interdigitated. Each electrode 344′, 345′ issubstantially identical and comprises a linear main track and aplurality of linear protrusions extending away from the main track, in adirection substantially perpendicular to the main track. Each electrode344′, 345′ comprises 125 protrusions, each protrusion having a lengthL_(P), of about 6760 μm, and a width W_(P), of about 10 μm. Neighbouringprotrusions are spaced apart by interspaces having a width W_(I), ofabout 30 μm.

The main track of the first electrode 344′ and the main track of thesecond electrode 345′ are arranged in parallel on the platform, at aseparation of about 6780 μm. The first electrode 344′ is arranged withits protrusions 346′ facing the second electrode 345′ and within theinterspaces of the second electrode 345′. The second electrode 345′ isarranged with its protrusions 347′ facing the first electrode 344′ andwithin the interspaces of the first electrode 344′. In at least oneexample embodiment, a consistent spacing of about 10 μm is providedbetween the first electrode 344′ and the second electrode 345′ along theentire length of the electrodes 344′, 345′.

In at least one example embodiment, the first and second electrodes arearranged on a platform, such as the platform of the sensor 343, is shownin FIG. 8. The sensor 343″ comprises a first electrode 344″ and a secondelectrode 345″ that are interdigitated. Each electrode 344″, 345″comprises a linear main track and a plurality of pairs of arcuateprotrusions, extending in opposite directions away from the main track.Each electrode 344″, 345″ comprises about 50 pairs of arcuateprotrusions. Each protrusion has a width of about 10 μm. Each pair ofprotrusions forms an incomplete circle that is not joined at thedistalmost end from the main track. Neighbouring pairs of protrusionsare spaced apart by interspaces having a width of about 30 μm. Thedistalmost protrusion of the second electrode 345″ comprises a completecircle.

The main track of the first electrode 344″ and the main track of thesecond electrode 345″ are arranged in coaxial alignment on the platformparallel on the platform, with the protrusions 346″ of the firstelectrode 344″ within the interspaces of the second electrode 345″ andthe protrusions 347″ of the second electrode 345″ within the interspacesof the first electrode 344″. The distalmost protrusion of the firstelectrode 344″ substantially surrounds the distalmost protrusion of thesecond electrode 345″. In this arrangement, a consistent spacing ofabout 10 μm is provided between the first electrode 344′ and the secondelectrode 345′ along the entire length of the electrodes 344′, 345′.

The cartridge 350 shown in FIG. 9 comprises a rigid housing 351 defininga liquid storage portion. The housing 351 comprises substantially planarsides. The internal volume of the housing 301 is sufficiently narrowthat capillary forces act on a liquid aerosol-forming substrate held inthe liquid storage portion. A sensor 353 comprises a first plateelectrode 354 and a second plate electrode 355 at opposite sides of theliquid storage portion. The electrodes 354, 355 form substantiallyparallel electrode plates having a length ranging from about 25 mm toabout 30 mm and a width ranging from about 5 mm to about 7 mm. Thiscorresponds to a cross-sectional area ranging from about 25 mm×5 mm toabout 30 mm×7 mm. The separation between the first and second electrodes344, 345 ranges from about 2 mm to about 3 mm.

The cartridge 350 further comprises aerosol-generator in the form of awick 352 extending from an end of the liquid storage portion and aheating coil 358 wound around the wick 352 at the distal end. Duringvaping, the coil 358 heats the wick 352 and atomises liquidaerosol-forming substrate in the wick 352. This draws liquidaerosol-forming substrate held in the liquid storage portion to the wickend of the liquid storage portion. The capillary forces caused by thenarrow separation between the first and second electrodes 354, 355 donot enable the liquid aerosol-forming substrate held in the liquidstorage portion to move freely. As a result, liquid aerosol-formingsubstrate collects at the wick end of the liquid storage portion and theliquid storage portion may be notionally divided into two sections, afirst section 38A towards the wick end that is filled with liquidaerosol-forming substrate and a second section 38B opposite the wick endthat is filled with air. As the liquid aerosol-forming substrate isconsumed during vaping, the second section 38B filled with air increasesin size and the first section 38A filled with liquid aerosol-formingsubstrate decreases in size.

The cartridge 360 shown in FIG. 10 comprises a substantially cylindricalhousing 361 comprising a central airflow passage extending therethrough. A liquid storage portion is defined between the housing 361 andthe central airflow passage, and comprises an annular body of carriermaterial. The cartridge 360 comprises aerosol-generator in the form of awick 362 extending across the airflow passage and a heating coil 368 inthe air passage and wound around the wick 362. The cartridge 360comprises a sensor 363 comprising a first electrode 364 and a secondelectrode 365 at opposite sides of the wick. During vaping, the coil 368heats the wick 362 and atomizes liquid aerosol-forming substrate in thewick 362. This draws liquid aerosol-forming substrate held in thecarrier material to the wick and changes the saturation of both the wick362 and the carrier material. As the saturation of the wick changes, theelectrical load between the electrodes, 364, 365 changes.

The cartridge 370 shown in FIG. 11 has a similar construction andarrangement to the cartridge 360 shown in FIG. 10. The cartridge 370comprises a sensor 373 comprising a first, circularly cylindrical plateelectrode 374 around the inner surface of the annular body of carriermaterial and a second, circularly cylindrical plate electrode 375 aroundthe outer surface of the body of carrier material. The first and secondelectrodes 375, 374 form concentric circularly cylindrical platesbounding the inner and outer surfaces of the annular body of carriermaterial. During vaping, the coil heats the wick and atomizes liquidaerosol-forming substrate in the wick, which draws liquidaerosol-forming substrate held in the carrier material to the wick. Thischanges the saturation of the carrier material, which changes theelectrical load between the electrodes 374, 375.

FIG. 12 shows a schematic circuit diagram of a sensor circuit 401 andcontrol system circuit 402 for an aerosol-generating system according tothe present invention. The sensor circuit 401 comprises a sensor 403, inseries with a resistor R and a dedicated sensor power supply to supplyan alternating voltage to the sensor 403 at a desired (or, alternativelya predetermined) frequency. The control system circuit 402 comprisescontrol electronics comprising a controller 404 and memory 405. Thecontrol electronics are connected to a power supply 406.

In other example embodiments (not shown) the sensor 403 may be connectedto the power supply 406, which may be configured to supply power to thesensor circuit 401 and the control system circuit 402. The power supply406 may also be configured to supply power to the aerosol-generator ofthe aerosol-generating system and the control system circuit 402 may beconfigured to control operation of the aerosol-generator.

In at least one example embodiment, an aerosol-generating systemcomprises one of the cartridges shown in FIGS. 2 to 12. During vaping,the aerosol-generating system is turned on by the adult vaper activatinga switch, and a control system of the aerosol-generating system suppliesan oscillating measurement signal to the first and second electrodes.The control system receives impedance information from the first andsecond electrodes and compares the measured impedance information toreference impedance information stored in a lookup table in a memory ofthe control system. The control system matches the measured impedanceinformation to a stored reference impedance information in the lookuptable. The stored reference impedance information is associated with aknown composition of liquid aerosol-forming substrate. The controlsystem indicates to an adult vaper that the composition of liquidaerosol-forming substrate is known by displaying the identity of theliquid aerosol-forming substrate on an LED display of theaerosol-generating system. In some example embodiments, the controlsystem is configured to control the power supply to aerosol-generator ofthe aerosol-generating system based on the determined identity of theliquid aerosol-forming substrate.

If the control system is unable to match the sensed impedanceinformation to a stored reference impedance information, the controlsystem displays to an adult vaper that the liquid aerosol-formingsubstrate is unknown or unauthorized. In some example embodiments, thecontrol system is configured to reduce and/or substantially preventoperation of aerosol-generator of the aerosol-generating system if theidentity of the liquid aerosol-forming substrate is unknown.

A calibration procedure may be performed for each aerosol-generatingsystem. In a calibration procedure, liquid aerosol-forming substrateshaving known compositions may be introduced into the liquid storageportion, and at least one of the inductance, resistance or capacitancemay be measured. The measurements may be stored in a lookup table in amemory of the control system, and each measurement associated with anidentity of liquid aerosol-forming substrate.

It will be appreciated that in other example embodiments (not shown),the control system may be configured to supply a measurement signal tothe first electrode and the second electrode that is not oscillating. Inother words, a direct voltage may be supplied to the first and secondelectrodes. In these example embodiments, the control system may beconfigured to measure the resistance between the first and secondelectrodes.

It will be appreciated that the relationship between the impedance,capacitance and resistance and the identity of the liquidaerosol-forming substrate will depend on the type and relative positionsof the electrodes relative to each other and the liquid storage portion.

It will be appreciated that in other embodiments (not shown) that thecartridges described in relation to FIGS. 2 to 12 may not be cartridges,but rather may be integral parts of aerosol-generating systems, such asthe aerosol-generating system shown in FIG. 1. It will also beappreciated that a main unit may be provided with sensors, such as thepairs of first and second electrodes shown in FIGS. 2 to 12, arranged tosense electrical quantities of liquid storage portions of cartridgesreceived by the main units.

It will be appreciated that features described for one exampleembodiment may be provided in other example embodiments. In particular,it will be appreciated that cartridges and aerosol-generating systemsaccording to the example embodiments may comprise more than one means ofdetermining the identity of the liquid aerosol-forming substrate held inthe liquid storage portion, such as more than one pair of first andsecond electrodes.

We claim:
 1. An aerosol-generating system comprising: a storage portionconfigured to hold an aerosol-forming substrate; a first electrode; asecond electrode spaced from the first electrode, at least a portion ofthe storage portion between the first electrode and the secondelectrode, and the portion of the storage portion between the firstelectrode and the second electrode containing the aerosol-formingsubstrate when the aerosol-forming substrate is held in the storageportion; and a control system configured to measure an electricalquantity between the first electrode and the second electrode, andidentify the aerosol-forming substrate held in the storage portion basedon the measured electrical quantity information.
 2. Theaerosol-generating system according to claim 1, wherein the controlsystem is configured to identify the aerosol-forming substrate held inthe storage portion by comparing the measured electrical quantityinformation to reference electrical quantity information stored in thecontrol system.
 3. The aerosol-generating system according to claim 1,further comprising: an aerosol-generator configured to receive theaerosol-forming substrate from the storage portion, and wherein thecontrol system is further configured to control operation of theaerosol-generator based on the determined identity of theaerosol-forming substrate held in the storage portion.
 4. Theaerosol-generating system according to claim 1, wherein the firstelectrode and the second electrode are on a platform of electricallyinsulating material.
 5. The aerosol-generating system according to claim1, wherein the first electrode and the second electrode areinterdigitated.
 6. The aerosol-generating system according to claim 1,further comprising: an aerosol-generator including one or moreaerosol-generating elements, and wherein at least one of theaerosol-generating elements includes at least one of the first electrodeand the second electrode.
 7. The aerosol-generating system according toclaim 1, further comprising: a power supply configured to supply thefirst electrode and the second electrode with a measurement signal. 8.The aerosol-generating system according to claim 1, wherein theelectrical quantity to be measured by the control system is impedancebetween the first electrode and the second electrode.
 9. Theaerosol-generating system according to claim 1, wherein the electricalquantity to be measured by the control system is resistance between thefirst electrode and the second electrode.
 10. The aerosol-generatingsystem according to claim 1, wherein the electrical quantity to bemeasured by the control system is capacitance between the firstelectrode and the second electrode.
 11. The aerosol-generating systemaccording to claim 1, wherein the system further comprises: a cartridgeincluding the liquid storage portion, and a main unit including thecontrol system, the main unit configured to removably receive thecartridge, and the first electrode and the second electrode arrangedsuch that a portion of the storage portion of the cartridge is betweenthe first electrode and the second electrode when the cartridge isreceived by the main unit.
 12. The aerosol-generating system accordingto claim 11, wherein the cartridge comprises the first electrode and thesecond electrode.
 13. The aerosol-generating system according to claim11, wherein the main unit comprises the first electrode and the secondelectrode.
 14. The aerosol-generating system according to claim 11,wherein the cartridge includes one of the first electrode and the secondelectrode, and the main unit comprises another one of the firstelectrode and the second electrode.
 15. A method of identifying liquidaerosol-forming substrate held in a liquid storage portion of anaerosol-generating system, the method comprising: measuring anelectrical quantity between a first electrode and a second electrode, aportion of a storage portion containing an aerosol-forming substratebetween the first electrode and the second electrode; and identifyingthe aerosol-forming substrate held in the liquid storage portion basedon the measured electrical quantity information.